182 results about "Coalbed methane extraction" patented technology

The invention belongs to the technical field of coal bed gas exploitation fracturing control, and particularly discloses a coal bed gas exploitation staged fracturing intelligent monitoring control system which collects rock samples from a target coal bed, conducts microstructure detection on the collected rock samples, removes the rock samples with natural fractures, and obtains the coal bed gas exploitation staged fracturing intelligent monitoring control system. Then a servo motor is used for applying the same stress in different directions to the rock sample for fracturing simulation, crack propagation monitoring is conducted after fracturing simulation, and therefore the crack propagation direction of the rock sample is associated with the stress applying direction to obtain crack propagation dominant microstructure distribution characteristics corresponding to the rock sample; the understanding of the crack propagation mechanism is deepened to the greatest extent, the definition of the crack propagation direction is increased, the crack propagation effect is optimized when fracturing operation is carried out in the coal seam without natural cracks, and the accuracy and effectiveness of fracturing are improved.

The invention discloses a method for exploiting coal bed gas by using an underpressure coal reservoir horizontal well group, which comprises the following steps that the horizontal well group is arranged, the horizontal well group comprises a preset number of horizontal wells, each horizontal well comprises a horizontal well section, and each horizontal well section is positioned in a coal reservoir of the same series of strata; each horizontal well section is divided into a plurality of fracturing sections with preset lengths, and perforation positions are selected in each fracturing section for perforation to form fracturing points; fracturing construction is carried out on each fracturing section, the fracturing construction comprises a liquid injection and energy charging fracturing stage and a main body fracturing stage, in the liquid injection and energy charging fracturing stage, a first part of liquid is injected into the coal reservoir through fracturing points at preset displacement and preset construction pressure so as to fill natural fractures and cleats of the coal reservoir, and in the main body fracturing stage, a second part of liquid is injected into the coal reservoir through the fracturing points at preset displacement and preset construction pressure so as to fill the natural fractures and cleats of the coal reservoir. Injecting a second part of liquid into the coal reservoir through the fracturing point to form an artificial fracture in the coal reservoir, wherein the preset construction pressure does not exceed the formation fracturing pressure of the area where the horizontal well group is located; and after fracturing of all the fracturing sections is completed, coal bed gas exploitation is conducted.

The invention belongs to the technical field of coal bed gas mining, and particularly discloses a multi-coal-bed mining optimization control method based on crossheading position stability, and the method comprises the steps: comprehensively obtaining parameters such as coal bed spacing, thickness, inclination angle, roof and floor lithology and fault distribution, and generating an accurate three-dimensional geologic model through three-dimensional modeling software; and the condition of incomplete geological analysis of a traditional method is changed. And on the aspect of crossheading arrangement, empirical operation is replaced with finite element analysis, the anchor rod distance and the support density are accurately determined, and safety and economical efficiency are improved. The mining sequence planning is changed from dependence on a fixed rule to establishment of an identification model combined with a genetic algorithm, and dynamic optimization is realized. The mining height, the mining width and the advancing speed are flexibly regulated and controlled according to the mapping relation table in the mining process, and real-time dynamic adjustment is achieved. Meanwhile, the early warning mechanism calculates scores based on crossheading stress data, is more accurate and sensitive, and has higher pertinence and effectiveness.

The invention belongs to the technical field of coal bed gas exploitation, and particularly relates to a method for achieving multiple purposes of a coal bed gas horizontal well. Firstly, a horizontal well is constructed in a coal seam, staged fracturing is conducted to increase permeability, coal bed gas ground extraction is achieved, when the coal bed gas yield cannot reach the economic recoverable condition, coal underground gasification is conducted through the horizontal well, and finally carbon dioxide obtained after gasification separation or other output is injected for storage through underground residual coal and coal cinder gaps. Multiple purposes of the coal bed gas horizontal well are achieved; through one-well multi-stage utilization, the functions of coal bed gas extraction, coal underground gasification, carbon dioxide storage and the like are achieved step by step, and the comprehensive cost is reduced by 40% or above.

The invention provides coal seam multi-section type directional fracturing and permeation increasing equipment and method, and relates to the technical field of coal mine gas treatment and coal seam gas exploitation, the coal seam multi-section type directional fracturing and permeation increasing equipment comprises a machine body, a propelling mechanism, a fracturing pipe and a liquid inlet mechanism, and a plurality of sets of directional assemblies are arranged outside the fracturing pipe at equal intervals; and the fixing mechanism is used for directionally spraying the high-pressure water to the fixed direction in the coal seam and comprises a limiting component arranged on the propelling mechanism and used for limiting the fracturing pipe stretching into the fracturing seam and a connecting component arranged on the limiting component and used for locking the fracturing pipe. High-pressure water can be directionally jetted to the fixed direction in a coal seam fracturing hole, the situation that due to the fact that the high-pressure water is jetted at will, a large number of cracks are generated on the soft portion of the coal seam, and consequently permeation increasing is uneven is avoided, in addition, a fracturing pipe stretching into the fracturing hole can be fixed, and the situation that the permeation increasing effect is affected due to the fact that the fracturing pipe shakes when equipment runs is avoided.

The invention relates to the technical field of drilling fluids, in particular to a preparation method of a plugging agent for shale and coal rock and a water-based drilling fluid, and aims to solve the problems that an existing plugging agent is poor in plugging effect on small cracks of shale and coal rock and poor in stability in a high-temperature environment. After the plugging agent for the shale and the coal rock is added into the water-based drilling fluid, the high-temperature-resistant nano polymer emulsion and the silane modified nano montmorillonite can enter small cracks of the shale and the coal rock to be mutually interwoven under the synergistic effect of the high-temperature-resistant nano polymer emulsion and the silane modified nano montmorillonite, so that a three-dimensional plugging network structure is jointly constructed, and the cracks are effectively plugged; the plugging agent can effectively prevent drilling fluid filtrate from invading the stratum, has excellent high-temperature resistance, is stable in structure in a high-temperature environment, can still keep good plugging performance under severe conditions of high temperature, high pressure, drilling fluid scouring and the like, and meets the high-temperature drilling requirements of deep shale gas and coal bed gas exploitation. And the safety and the efficiency of drilling operation can be improved.

The embodiment of the invention relates to the technical field of coal bed gas drainage, and particularly discloses a liquid drainage device, a liquid drainage pump and coal bed gas exploitation equipment, the liquid drainage device comprises a pipe body, a piston and a one-way valve, the pipe body is internally provided with a containing cavity, one end of the pipe body is provided with a liquid outlet communicated with the containing cavity, and the other end of the pipe body is used for being connected with a lifting device; the peripheral wall of the pipe body is further provided with a liquid drainage hole which can enable the containing cavity to be communicated with the outside of the pipe body, the piston is movably arranged in the containing cavity, a liquid passing hole is formed in the piston, the end, away from the liquid outlet, of the liquid passing hole is used for being communicated with a lifting device, and the one-way valve is arranged in the containing cavity and connected to the end, facing the liquid outlet, of the piston. The one-way valve is communicated with the liquid passing hole, the piston can move between a first position and a second position relative to the pipe body, in the first state, the fluid can be discharged from the liquid outlet of the pipe body, and in the second state, the fluid can be discharged from the liquid discharging hole of the pipe body. In this way, deposition of solid particles in the pipe body can be reduced.

The invention belongs to the technical field of coal bed gas exploitation, and particularly relates to an extraction system and method for high-pressure air blasting and hot flue gas displacement of coal bed gas. The system comprises a high-pressure air blasting unit, a hot flue gas injection unit, a gas extraction unit and a data monitoring unit, the high-pressure air blasting unit and the hot flue gas injection unit share the same blasting and gas injection well, an extraction well is arranged on the outer ring of the blasting and gas injection well, and the gas extraction unit extracts gas through the extraction well; the coal seam is subjected to fracturing and permeability increasing through high-pressure air blasting, the coal seam can be effectively fractured, and the permeability of the coal seam can be effectively improved; hot flue gas is injected after high-pressure air blasting permeability increasing is conducted on the coal seam, the hot flue gas can be smoothly injected into the coal seam, and the coal seam is further fractured; the temperature of the coal seam can be increased by injecting the hot flue gas, desorption and migration of CH4 are facilitated, meanwhile, CH4 in an adsorption state is replaced by CO2 by means of the adsorption characteristic of CO2, and CO2 is effectively sealed in the coal seam while the desorption amount of the coal seam gas is increased.

The invention discloses a coal bed gas exploitation method for promoting microbial gasification synergy under the action of electric-magnetic double fields, and belongs to the technical field of coal bed gas exploitation. The method comprises the following steps: fracturing a coal reservoir through an injection well to form a fracture network; injecting an electrolyte solution and a microbial solution into the fracture network, wherein the microbial solution contains flora induction particles; applying an electric field to the coal reservoir, and controlling the flora of the microbial solution and flora-induced particles to migrate in the fracture network; then applying a low voltage field to promote further communication of branch fractures in the fracture network, and inducing migration again; applying a magnetic field to the coal reservoir; microorganism proliferation and uniform distribution are promoted, organic matter decomposition and methane release in the coal seam are accelerated, and the coal seam gas yield is increased.

The utility model relates to the technical field of coal bed gas exploitation, and discloses a water-gas separation device for coal bed gas exploitation, which comprises a separation box, and one side of the separation box is provided with a gas inlet. The coal bed gas is input into the separation box through the gas inlet and impacts on the gravity separation plate, the coal bed gas is blocked by the gravity separation plate, and meanwhile, the contact area with the coal bed gas is greatly increased through the multiple water guide plates and the vertical water guide plates, so that a mixture of water and the coal bed gas flows downwards, and due to the fact that water drops deposit downwards due to the weight, gas moves upwards; when the coal bed gas passes through the first umbrella-plate separator, large water drops carried by the coal bed gas are separated, the water drops are condensed on the first umbrella-plate separator and flow downwards, rising natural gas passes through the third umbrella-plate separator, then fine water drops carried by the coal bed gas are separated through the foam breaking net, and the fine water drops are condensed into large water drops to sink down. And the coal bed gas with separated water is discharged from an exhaust port, and the sinking liquid also passes through an umbrella plate separator II, so that the sinking liquid is broken and dispersed.

The invention relates to a condensate-oil-resistant and temperature-resistant foam scrubbing agent for deep coal bed gas exploitation and a preparation method of the condensate-oil-resistant and temperature-resistant foam scrubbing agent. The method comprises the following steps: (1) mixing 45-55 parts of sodium 3-chloro-2-hydroxypropanesulfonate and 14-28 parts of lauryl sodium sulfate, dissolving in an aqueous solution containing a special additive, adding 70-110 parts of aliphatic tertiary amine, heating to dissolve the aliphatic tertiary amine, adding the mixed solution into a three-neck flask, adjusting the pH value, heating, adjusting the pH value once every 25-35 minutes, reacting at 70-90 DEG C for 6-8 hours, and cooling to obtain a reaction solution; obtaining a yellow viscous product, namely the long-chain fat hydroxypropyl sulfonated betaine; and (2) adding 5-10 parts of a mixture of polyacrylamide and cellulose and 1-8 parts of nanoparticles into 80-150 parts of a product obtained in the step (1) to obtain the condensate oil-resistant temperature-resistant foam scrubbing agent. The lowest surface tension of the foam scrubbing agent can reach 28.12 mN / m, the foam scrubbing agent is high in foaming capacity, the foam height in clear water can reach 980 mL, the half-life period in high condensate oil content can reach 350 s, the condensate oil content reaches 35%, the foam height can still reach 750 mL, and the liquid carrying rate can reach 83.2%.

The invention relates to the technical field of coalbed methane exploitation, in particular to a horizontal well blockage removing and yield increasing coalbed methane device and method. Comprising an injection system, a pumping system, a monitoring system, a safety system and a propelling system. Modular design and compact layout are adopted, and blockage removal liquid is sprayed into reservoir fractures through injection systems such as a liquid injection pipe, a mounting rod, a mounting opening and a high-pressure spray head; conveying and shunting of the suspended sand blockage removal liquid are realized through pumping systems such as a liquid injection port, a suction pump, a liquid injection pipe, a flowback pipe and a shunting pipe; the sand-suspending plug removal liquid is injected into the horizontal well pipeline through the liquid injection pipe, enters the high-pressure spray head in a split-flow and split-direction mode through the split-flow pipe and enters the reservoir fracture under the pressurization effect of the high-pressure spray head for acidification plug removal, and multiple times of circulating plug removal are completed through multiple times of repeated action. According to the invention, through repeated circulating plug removal, the plug removal and yield increase efficiency is improved, and remarkable economic and social benefits are achieved.

The invention discloses a method for enhancing coalbed methane recovery efficiency by an external magnetic field, which comprises the following steps of: arranging a plurality of electrified coils or magnetic field generators connected with a power supply in a coalbed to generate an alternating magnetic field in the coalbed; cH4 molecules show diamagnetism under the action of a magnetic field, a repulsive effect is generated in a coal seam, and the adsorption effect of CH4 and a coal body is weakened; and on the other hand, as the coal body contains ferromagnetic or paramagnetic minerals, the alternating magnetic field excites the annular eddy current in the coal body through electromagnetic induction so as to generate Joule heat. Therefore, coal matrix expansion and microfracture expansion can be induced by temperature rise of the coal body, the permeability of the coal body is further improved, and more channels are provided for CH4 desorption and flowing; the clean, efficient and environment-friendly coal bed gas exploitation method is provided on the basis of superposition of multiple production increasing mechanisms, and a new technical approach is provided for exploration and development of unconventional oil and gas resources.

The invention discloses a soft coal seam nanofluid fracturing propping material and a preparation method thereof.The soft coal seam nanofluid fracturing propping material is prepared from, by weight, 80-90% of a base material, 1-5% of a super-hydrophobic coating, 5-10% of a catalytic active component and 5-15% of a rheological enhancer, the base material is a compound of high-purity silicon dioxide nanoparticles and graphene nanosheets GNP, the particle size of the high-purity silicon dioxide nanoparticles is 50-200 nm, the super-hydrophobic coating is a fluorosilane modified layer, the thickness of the super-hydrophobic coating is 5-20 nm, and the invention relates to the technical field of coal bed gas exploitation. According to the soft coal seam nanofluid fracturing propping material and the preparation method thereof, the surface of the material is provided with a super-hydrophobic coating, friction force with a coal matrix is reduced, high embedding resistance is achieved, the flow conductivity is specifically enhanced, an extra flow channel is provided through a porous nanostructure, the fracturing fluid permeability is improved, and meanwhile gas desorption can be cooperated; catalytic active sites are introduced to the surface of the material to promote adsorption and diffusion of methane molecules.

The invention belongs to the technical field of coal bed gas exploitation and carbon dioxide geological storage, and relates to a coal bed carbon dioxide injectability evolution whole process simulation device and method, and the device comprises a true triaxial stress loading system, a temperature control system, a multi-mode gas injection system, a monitoring system, and a data processing system. The deep stratum stress state and the stratum temperature field are simulated, constant-pressure and constant-current mode carbon dioxide is injected into the true triaxial stress loading system to carry out groutability attenuation and recovery simulation, and nitrogen and pulse mode injection is switched to carry out temperature change regulation and control, phase change regulation and control and frequency change regulation and control so as to simulate groutability improvement. According to the method, a whole-process evolution mechanism of attenuation-recovery-improvement of carbon dioxide groutability is realized, meanwhile, data acquisition and permeability and stress calculation are performed through a monitoring system and a data processing system, and rapid conversion from original data to core parameters is realized; and accurate experimental data support is provided for on-site injection parameter optimization and regulation and control technology research and development.

The invention discloses a gas-liquid-sand separation, defoaming and metering device. The device comprises a vertical separator, a separation assembly, a defoaming assembly, a gas phase flowmeter and a liquid phase flowmeter, wherein the separation assembly and the defoaming assembly are arranged in the vertical separator; wherein the upper part and the lower part of the vertical separator are respectively connected with the gas phase flowmeter and the liquid phase flowmeter; according to the integrated gas-liquid-sand separation, defoaming and metering device for coal bed gas exploitation, the desanding function, the gas-liquid separation function, the defoaming function and the metering function are integrated, the occupied area is reduced, the treatment process of gas-liquid-sand mixed fluid is simplified, then the production efficiency is improved, and the production cost is reduced.

The invention discloses a coal bed gas exploitation and separation utilization method based on SCCO2 assistance, and belongs to the technical field of coal bed gas development. Supercritical carbon dioxide is prepared through a high-pressure reaction kettle and stored in a supercritical carbon dioxide storage and collection tank, meanwhile, nitrogen mixed with graphene is introduced, and CO2 / CH4 adsorption selectivity is enhanced by means of the characteristic that the specific surface area of graphene is large. A variable-frequency sound wave diffuser is matched to excite coal seam micro cracks through low-frequency sound waves, and supercritical carbon dioxide and nitrogen mixed gas is injected into a coal seam injection well. In the injection process, the sound wave diffuser synchronously radiates high-frequency sound waves to improve the displacement efficiency, then the gas enters the gas separation tower integrated with the molecular sieve membrane, and the produced gas is divided into upper methane, middle carbon dioxide and other bottom miscellaneous gas. Methane is pressurized by an air compressor and then stored in a methane storage tank, carbon dioxide is purified and pressurized and then recycled for coalbed methane exploitation, and offensive gas is cooled and stored after generating power by a steam turbine. And efficient mining, separation and multi-path utilization of the coal bed gas are realized.

The invention relates to the technical field of coal bed gas exploitation equipment, in particular to adjustable multi-layer co-exploitation equipment and method for coal bed gas exploitation, and aims to solve the problem that blockage removal and maintenance are needed frequently in the prior art. Comprising an installation base plate anchored to the ground, a well casing pipe used for being inserted into a mine is arranged on the installation base plate, a sealing cover is arranged at the upper end of the well casing pipe in a matched mode, a gas production pipe used for conveying natural gas is arranged at the upper end of the sealing cover, and a plugging component used for plugging multiple gas layers is arranged on the well casing pipe. The device is designed according to existing needs, the problem that underground water is pumped out by constructing a negative pressure structure, a pump body is damaged by impurities in the water is solved, the service life of the device is effectively prolonged, in addition, underground water can be filtered, coal in the underground water can be rapidly recycled, resource waste is avoided, and the device is worthy of popularization and application. And hole cleaning operation can be automatically completed while coal materials are recycled and filtered, continuous work of equipment is guaranteed, and the use efficiency is guaranteed.

The invention relates to the technical field of oil and gas field and coal bed gas exploitation engineering, in particular to an underground gas-water two-phase jet flow drainage and mining device and a using method. According to the technical scheme, more than one group of leather cups are arranged on the outer wall of the lower side of a hydraulic pump body, and the upper end of the hydraulic pump body is connected with the lower end of a pneumatic pump body through an upper connector of the hydraulic pump; an air distributing and collecting umbrella pipe is installed on the outer side of the pneumatic pump body, a pneumatic throat pipe, a liquid drop micronizer and a pneumatic nozzle are arranged in the pneumatic pump body, a pneumatic diffusion cavity is formed in the upper portion of the pneumatic throat pipe, the pneumatic nozzle is arranged on the lower portion of the pneumatic throat pipe, the liquid drop micronizer is arranged on the upper side of the pneumatic throat pipe, and the lower end of the pneumatic nozzle is connected with an air inlet. The upper end of the pneumatic nozzle is communicated with the mixed liquid channel. The hydraulic pump has the advantages that the hydraulic pump body and the pneumatic pump body are designed to be integrated into an organic whole, the structure is compact and novel, high-pressure water jet speed-increasing atomized liquid flow and high-pressure gas jet flow are integrated to achieve jet flow drainage and mining, the lifting lift is greatly improved, and the negative-pressure suction and plug removal effects are also achieved on other blockages in a production layer.

The present invention relates to the field of underground coalbed methane extraction, and discloses a coal underground gasification injection-production linkage control system and method, which includes a formation, an injection wellhead device, a winch, a production wellhead device, a main control station, an underground gasification and reaction control unit, a gasifying agent production unit, a heating unit, a first vent pipeline, a second vent pipeline, an underground coal gas production and state control unit, a raw coal gas treatment unit, and a flare system. The system adopts a distributed control system design to realize the integrated automation control of injection and production in coal underground gasification, improve the automation degree of underground coalbed methane extraction; and can change the control scheme according to different control processes, with high system flexibility; adopts a multi-channel cascade closed-loop control loop to realize the multi-variable coupling control of temperature, pressure, flow, etc., and reserves interfaces for intelligent algorithms and prediction models to solve the large lag problems brought by the analysis of raw coal gas components and the data transmission process.

The utility model discloses a pulverized coal filtering and collecting device for coal bed gas exploitation, which comprises a filtering and collecting box, the filtering and collecting box is of a hollow structure, an air inlet pipe is arranged at the upper end of the side face of the filtering and collecting box, one end of the air inlet pipe is arranged in the filtering and collecting box, and the other end of the air inlet pipe is arranged outside the filtering and collecting box. An air outlet pipe is arranged at the upper end of the side face, away from the air inlet pipe, of the filtering and collecting box, one end of the air outlet pipe is arranged in the filtering and collecting box, the other end of the air outlet pipe is arranged outside the filtering and collecting box, a filtering assembly is arranged on the filtering and collecting box, and a cleaning assembly is arranged at the lower end in the filtering and collecting box and arranged below the filtering assembly. The utility model relates to the technical field of coalbed methane exploitation, in particular to a pulverized coal filtering and collecting device for coalbed methane exploitation.

The application discloses a method for exploiting coalbed methane by using a horizontal well group in a coal reservoir with an underpressure type, which comprises the following steps: arranging a horizontal well group, the horizontal well group comprising a predetermined number of horizontal wells, each horizontal well comprising a horizontal well section, and each horizontal well section being located in a coal reservoir of the same layer system; dividing each horizontal well section into a plurality of fracturing sections with a predetermined length, perforating a perforation position in each fracturing section to form a fracturing point; performing fracturing construction on each fracturing section, the fracturing construction comprising a liquid injection and energy storage fracturing stage and a main fracturing stage, in the liquid injection and energy storage fracturing stage, a first part of liquid is injected into the coal reservoir through the fracturing point at a predetermined discharge capacity and a predetermined construction pressure to fill natural fractures and cleats of the coal reservoir, in the main fracturing stage, a second part of liquid is injected into the coal reservoir through the fracturing point to form artificial fractures in the coal reservoir, and the predetermined construction pressure is not higher than a formation fracture pressure of a region where the horizontal well group is located; and after all the fracturing sections complete fracturing, coalbed methane exploitation is performed.

The utility model relates to the technical field of coal bed gas exploitation, and discloses a coal bed gas ground well fracturing and yield increasing device which comprises fracturing main body units, fracturing device connecting pieces, variable connecting pieces, a drainage pipe, a hole sealing device and a cable, the fracturing device connecting pieces are installed between the fracturing main body units, the variable connecting pieces are installed at the upper ends and the lower ends of the fracturing main body units, and the drainage pipe is installed between the fracturing main body units. The drainage pipe is installed on the surface of the variable connecting piece, the hole sealing device is installed on the surface of the drainage pipe, and the cable is electrically connected to the fracturing body unit. The coal bed gas ground well fracturing yield increasing device is convenient, stable, safe and efficient for the CO2 fracturing coal bed gas control technology, the direct acting radius of the CO2 fracturing technology is 1.5-5 m, the influence radius can reach 15 m, the gas extraction drilling work amount is reduced by 30%-60%, the duration time of high-concentration and large-flow gas extraction is long, the gas extraction lower limit is effectively reduced, and the gas extraction efficiency is improved. The method is suitable for coal seams with different firmness coefficients, and has a better application effect in coal seams with strong gas adsorbability.

The invention discloses a self-excited oscillation filtration coal powder system used in the coalbed methane mining process, the system comprises: an outer cylinder seat, an end cover, a spring assembly, a filter assembly, an oscillation sheet, a water inlet pipe, a water outlet pipe and a sand pump; the outer cylinder seat is a cylindrical body with a chamber provided therein, and a hole is opened at the center of the bottom; the upper pipe opening of the water inlet pipe extends upward from the hole at the bottom of the outer cylinder seat into the inner cavity of the outer cylinder seat; the lower pipe opening of the water inlet pipe is downwardly connected to the coalbed methane mining well; the end cover sealing cover is closed at the upper end of the outer cylinder seat; the center of the end cover is provided with an air outlet connected to an external coalbed methane gas production pipeline; the end cover, the spring assembly, the filter assembly and the oscillation sheet are connected in sequence from top to bottom; the filter assembly surrounds the air outlet; the oscillation sheet is suspended directly above the pipe opening of the water inlet pipe; a water outlet is provided at the bottom of the outer cylinder seat; and the sand pump is connected to the water outlet through the water outlet pipe. The invention effectively separates coalbed methane from coal powder, and the coalbed methane and coal powder are collected separately, thereby improving the extraction efficiency.

The invention is suitable for the technical field of coal bed gas exploitation safety, and provides an underground coal bed gas collection monitoring and safety early warning method and system, and the method comprises the steps: obtaining the state parameters of a target region, and building a comprehensive gas diffusion analysis model covering the internal space of a pipeline, a coal bed crack and an underground roadway; simulating gas flow and concentration change based on the model, and generating a first installation scheme of the pipeline sensor; in combination with coal seam geology and ventilation parameters, simulating a coal seam gas dissipation direction and a convergence area, and generating a second installation scheme including acquisition equipment arrangement; and a real-time data transmission network is constructed, abnormal data are identified through space-time correlation analysis, equipment faults and real leakage are distinguished, and early warning is performed. The system corresponds to the method. According to the method, the monitoring layout is optimized through the comprehensive model, the anomaly recognition precision is improved, comprehensive and accurate safety early warning is achieved, and the mining safety of underground coal bed gas is guaranteed.

The utility model relates to the technical field of coal gas mining equipment, and discloses an underground coal bed gas mining and desanding device, a top gas pipeline is arranged at the top of a bottom gas pipeline, a desanding and water filtering assembly is arranged between the bottom gas pipeline and the top gas pipeline, and a desanding and water filtering assembly is arranged between the bottom gas pipeline and the top gas pipeline. The desanding and water filtering assembly is arranged between the bottom gas conveying pipeline and the top gas conveying pipeline, the desanding net barrel in the desanding and water filtering assembly can filter large-particle sand contained in conveyed coal gas, and the dust filtering net can filter fine dust again. After activated aluminum oxide powder is filled in the aluminum oxide storage net cylinder, water molecules contained in the coal gas passing through the aluminum oxide storage net cylinder can be adsorbed and removed, so that water and gravel particles contained in the coal gas discharged outwards can be effectively removed and purified; water is prevented from being mixed with dust particles to adhere to the inner wall of the pipeline, and it is guaranteed that coal gas conveying is safer and more reliable.

The invention provides a multilateral well coalbed methane extraction method, which comprises the following steps of: selecting one coal seam with one or more coal seams with higher coalbed methane content above as an extraction coal seam, and arranging a dense rib multilateral well coalbed methane extraction system in the adjacent coal seam at the upper part before coal seam extraction work is propelled to the extraction coal seam, and then coal bed gas extraction is carried out. According to the extraction method, efficient extraction of the coal bed gas close to the coal seam and flowing of the coal bed gas (gas) into the goaf and the roadway are effectively achieved, and scientific guidance is provided for effectively implementing co-extraction of the coal gas in the thin-medium thick coal seam group.

This invention discloses a simulation device for gas and water production in coalbed methane fracturing wells, comprising a base, a support with an arc-shaped cross-section fixed on the base, a wellbore placed on the support, end cap assemblies connected to both ends of the wellbore, a vertical rod fixed to one side of the base, one end cap assembly hinged to the bottom of the vertical rod, a pulley at the top of the vertical rod with a rope wound around it, the rope connected to the end cap assembly at the end furthest from the vertical rod, and a winch at the lower end of the vertical rod for winding the rope. Compared with existing technologies, this invention fully considers the simulation requirements under different working conditions, providing researchers with a comprehensive and controllable experimental platform, facilitating in-depth research on various influencing factors in the coalbed methane fracturing process, and providing a more scientific theoretical basis and experimental evidence for coalbed methane extraction.

The present invention discloses a downhole screen with a self-cleaning function, comprising a screen body, a transmitting transducer, a flow sensor, a controller, and a power supply device disposed within the screen body. The transmitting transducer is disposed in the middle section of the screen body, its axis parallel to the axis of the screen. The flow sensor is disposed at one end of the screen body near the water outlet, and the controller is electrically connected to the transmitting transducer, flow sensor, and power supply device. This downhole screen can effectively clean impurities clogged between the screen wire wraps or slits, ensuring normal pump fluid supply, extending the pump inspection cycle, improving the pumping efficiency of oil and gas wells, and reducing coalbed methane extraction costs.

The utility model discloses a kind of deep coalbed gas exploitation sampling devices, including shell, the shell inside is provided with inner bag, the hollow inside the inner bag, top and bottom are separately provided with communicating pipe and sampling pipe, the communicating pipe and sampling pipe are respectively worn out shell and with shell sliding connection, the inner bag is slidably arranged with sealing plate, the sealing plate top is fixedly provided with connecting frame, the connecting frame top is penetrated by screw rod and is connected with screw rod, the connecting frame top is provided with recess and the recess is slidably connected with limit rod, the limit rod one end is fixedly connected with inner bag, the screw rod one end is connected with motor fixedly installed in inner bag inside, by setting sampling device in inner bag, put inner bag in shell to protect inner bag, and set spring for buffering between inner bag and shell to buffer external impact force, and by setting counterweight that can be disassembled between each other, it is convenient to adjust counterweight.